The invention relates to improvements in ventilated seat cushions, such as those commonly used in automobiles, boats, aircraft, and the like.
Heretofore, a very widespread type of cushion construction employed coiled wire enclosed by a casing or cover of fabric. However, coil spring cushions exhibit numerous shortcomings, such as eventual rusting of the metallic coil springs, damage to the flexible covers caused by the abrasive action of the coil springs, discomfort to the user owing to sharp ends of the wires protruding through the covers, inability of overstressed cushions adequately to support the user, with consequent loss of proper ventilation, and relatively high cost.
Improvements in the design of seat cushions were forthcoming, and the most promising proposals supplanted the metal coils with a support system based on "plastic" constructions of various kinds.
For example, Trotman U.S. Pat. No. 3,162,487, uses a thin, flexible, plastic sheet including a plurality of vacuum-formed hollow projections upon which the seat cover is supported. In contrast, the present invention includes a support system comprising a plastic grid-like framework having fore and aft and transverse stiffening ribs with discs, or pads, located at the bottom of the rib intersections. While Trotman relies on circular openings interspersed between the projections in the plastic sheet to enhance ventilation, the present invention enjoys virtually all of the open space defined by the grid pattern for ventilation, excepting the relatively small area covered by the discs, the lower edges of the ribs of the grid framework and the marginal band. Thus, the present invention represents a significant improvement over Trotman owing to the substantial increase ventilation afforded by the present invention.
Another example, Goldstein U.S. Pat. No. 2,931,427, illustrates the use of a grid-like support framework overlaid by a perforated seat cover. While the grid-like framework disclosed therein somewhat resembles that of the present invention, several important distinguishing features exist. The ventilating apertures in Goldstein, for example, are found only in the fore and aft rows of ribs, and even then, only in the lower portion of those ribs. In the present construction both transverse and fore and aft ventilation channels are provided and the air flow channels are located on the upper or outer edges of the ribs for optimum cooling effect owing to the proximity to the user's body.